Combined circuit breaker



UnitedStates Patent M COMBINED CIRCUIT BREAKER Zachrah Berl Rowell and Ralph W. Easterwood, Midland,

Tex asiguors of one-third to C. E. Vaughan, Midland, Tex.

] Application January 17,1958, Serial No. 109,492

4 Claims. 01. zoo-451.47

cargos of inflammable material such as gasoline or butane. Often these fires start from the electrical system of the vehicle. We have invented a circuit breaker which will open the ignition circuit of the vehicle'if the vehicle as a whole receives suflicient impact or if the vehicle as a whole tilts as it would occ r if the vehicle turns over without an impact. Although i. is primarily designed to be used on the ignition circuit, it would be useful on any circuit, i.e. it-could be connected to those circuits containing the ignition, the radio and other accessories.

It would not be desirable to have the starter, or the lights,

or the horn of the vehicle operating through this circuit breaker. However, the circuits which are wired through the circuit breaker would be at the option of the user.

An object of this invention is to provide a circuit breaker Whichwillopen if the breaker receiveseither an impact or a tilt.

Another object of this invention is to provide a breaker which has an adjustment with a corresponding scale so that the amount of impact which will open the breaker may be adjusted to predetermined amounts.

Another object of this invention is to provide a breaker wherein no current passes through the spring which biases the impact device in place whereby the amount of impact will not change with time.

A further object of this invention is to provide a breaker whereby the impact device is held only in one area and even if welding occurs because of the flow of currents at electrical junctions, it will not be as critical as if the device were held in two areas.

Still further objects are to achieve the above with a device that is sturdy, simple, and reliable, yet cheap and easy to manufacture.

The specific nature of the invention as well as other objects, uses, and advantages thereof will clearly appear :from the following description and from the accompany- Iing drawing, in which:

Fig. 1 is a plan view of the device according to this invention.

Fig. 2 is an axial section of the device taken on lines 2-2 of Fig. 1.

Fig. 3 is a cross-section of the post taken on lines 3-3 of Fig. 2.

Fig. 4 is a detail of the washer seat wherein the ball :sets.

As seen in the accompanying drawings, one embodimeat of this invention is contained in a general cylindrical body or frame 10. The lower portion 12 of the body curves inward for the reason which will be explained later. This inward curve may be in either a spherical -or conical manner. A strap 14 extends around the cir cumference of the body to hold .it to a supporting wall.

2,912,534 Patented Nov. 10, 1959 2 The strap fits in annular groove 16 and has cars 18 which have apertures 20 for bolts.

A ball 22, made of conductive material, is supported on a post 24. The ball rests in a concave seat as shown. A cap 26 of insulatingmaterial, also with a concave seat, is spring biased downwardto hold the ball on the post.

A metal insert 28 is cast into the top of the "body 10. It is contemplated that the body 10 will be' made of a nonconductive transparent material. Along the axis of the body, there is a threaded opening 30 in the metal insert. Screw 32 is threaded through this opening and a lock nut 34 is clamped around the screw above insert 28 so that the screw may be securely held in any adjusted position. Adjacent to the lower end of the screw is a flange 36 which also carries a pointer 38. Spring 40 extends from the flange 36 to the cap 26. If the screw is lowered, the tension of the spring will increase, or if it is raised, the tensionwill decrease. Therefore, a scale 42 is provided for cooperation with the pointer 38 so that the amount of tension with which theball is held in its seat may be determined. a

The post 24 is of a nonconductive material of genera cylindrical shape. There is a shoulder 44 near the lower end thereof. Cast within the post and extending generally parallel to the axis thereof are leads 46 and 48. The lower end of each of these leads terminates'with a screw connection to each of which an electrical wire may be I attached. The top of wire terminates with a half washer 50. An aperture 52 is provided in the half washer so that the wire may be soldered or otherwise electrically closed by insulating washer 56. The lower end. of the cavity is conical or spherical shaped as seen at-58 Within the cavity is'asmall pool of mercury or other conductive liquids 60. Depending from another half Washer 62 is a short lead 64 which is long enough to reach the pool of mercury, but not long enough to contact the wire 48.

The bottom of the body 10 contains an annular axial boss 66 which has external threads. A nut 68 has mating internal threads and on the bottom of the nut there is an inward turned flange 70. As may be seen, the inward turned flange cooperates with the shoulder 44 so as to hold the post in position.

In operation, the hot wire from the battery would be connected to the post leading to wire 46 and a circuit to be disconnected would be connected to the post connected to wire 48. In operation, there will be a flow of current through wire 46, half washer 50, conductive ball 22, back through half washer 62, depending lead 64, mercury pool 60, and wire 48. The spring 40 has no current passing through it; therefore, there is no possibility of the spring heating or otherwise being'aflected so that its spring constant would be changed, giving a different pressure than indicated on the ball 22. In case of an impact, the momentum of a ball 22 will carry it out of the socket, thereby interrupting the circuit. The force of the impact will cause the ball to be loaded as a cantilever, if for some unexpected reason some slight welding occurs between the half washers and the ball. It will only be attached to the bottom area, the top will be free and it will be more likely to come loose than if it were connected to both top and bottom areas.

The impact that causes the ball to leave the seat will be determined as noted by the pressure. The scale 42 may be calibrated in numerous ways. For instance, it could be calibrated by the weight of the vehicle. It would be desirable for a heavy truck to have the circuit open at a lesser impact than for a light sports car. There could be a general indication of the top half of the scale designated trucks and the bottom half of the scale designated as automobiles. The circuit will be opened upon impact of the device.v as a whole. The b is transparent so that the pointer may be seen on the scale 42.

If for some reason, the imp ct was insuflicient to cause serious damage, and after inspection, it has been determined, that there is no likelihood of fire, the. device m y be reset by unscrewing the nut 68. and allowing the post todrop. The flange 7-2 on the top of the post will fit in recess 74- so that the post will not come out of the device. The top of the post will be. flush with the bottom of the interior of the housing 10. The conic or spherical walls 12 at the bottom of the housing willcause the ball 22 to roll onto the. seat provided by the, half Washers 62 and 5.0. When they post is: raised into position and the nut 68Mscrewed securely in, place and the circuit is completed as before;

If the vehicle tilts over, without impact'occurring the circuitv will be broken, vIntbis case,v the mercury pool 60 will flow away from theapex of the, lower conic surface; 58.; and along the wallsof the cylinder. Therefor h r will. not be. electrical contact betweenwire 48 and; lead tid i 7 It will'be apparent that the embodiments shown are only exemplary and that various. modifications can be made in construction, materials, and arrangement within the, scop v of the invention as defined intheappended claims.v

We im aso rinvention: 7

. 1. A combinedcircuit breaker comprising: a housing, a vertical post within the housing, said post attached to the bottom of the. housing, a concave seat on the top of the post, an electrical lead connected to the seat and depending therefrom, a ball on the seat, a spring dependingfrom thetop of the. housing, said spring biasing the ball toward the seat, an insulating cap between the spring-fandtthe ball, a cavity within the post, a pool of conductive liquid within the cavity, said electrical lead terminating within said pool, a first electrical terminal on; the outside of the housing, said first electrical terminal 4 electrically connected to said pool, a second electrical termination the outside of the. housing, and an electrical connection from the second terminal extending through the post to the ball; whereby if the ball leaves the seat the electrical circuit from the first to second terminal is broken, or if the conductive liquid flows from position said electrical circuit is broken.

2. The invention as defined in claim 1 with the addition of a screw in the housing opposite the, post, and aligned with the post, a flange on the end of screw nearest the post, said spring extendingfrom said flange toward" the post; whereby as the screw is advanced toward theseat,

V the force holding the ball on the seat is increased.

3. The invention as defined in claim, 2 with the addition of a scale depending from the inside of the housing parallel and nearthe screw; and-a pointer on the screw, and wherein the housing is constructed of transparent material whereby the strain on the spring may be adjusted to predetermined, values. .i

4, The, invention as, defined in claim 1, wherehrthe post is, mounted for vertical movement in; the housing, means for holding the post at the upper limit of the. travel of the post, and the, bottom of the housing sloping inward, so arranged and constructed that if the post is moved downward. the ball, rolls along the. slopingbottom and onto theseaton, top the post,

References, Cited in the-file of this patent.

UNITED STATES PATENTS 2,056,494 

